fieldset {
  width: 200px;
}

div {
  background-color: black;
  padding: 10px;
  width: 50px;
  height: 50px;
}

fieldset div {
  background-color: red;
}
fieldset:enabled div {
  color: aqua;
  background-color: green;
}
fieldset:enabled > div {
  background-color: yellow;
}

/* Add an unnecessary :first-child to make sure that restyle hints see
 * non-rightmost pseudo-selectors.
 * */
fieldset:enabled:first-child ~ div {
  color: pink;
  background-color: purple;
}
fieldset:enabled:first-child + div {
  color: brown;
  background-color: orange;
}

input:checked:enabled + span {
  color: khaki;
}
input:checked:disabled + span {
  color: lawngreen;
}
